There have been many prior art approaches to the comminuting of hard materials with the most common approach being the use of the hammer mill, ball grinding, jet milling, etc. They tend to involve a high degree of wear and tear on the apparatus, have high energy requirements, and lack means for enabling a flexible and accurate control as to the desired size and uniformity of size of the resulting product attained.
The need for a higher speed, lower energy consumption, low wear comminuting apparatus continues to be a priority for industry. Fossil fuel electric power generating stations must pulverize coal before it can be injected into their boilers. Currently available pulverizing methods (typically ball mills) pulverize at a slow rate, require recycling of oversize product, and require replacement of the balls as they wear out.
Similarly, mineral ores usually require that they be pulverized before processing to separate the mineral from its gangue. Roller mills, ball mills, and the like present problems for the processing company with their inherent slow speeds, size classification and subsequent recycling of oversize product, high energy consumption per ton of feed, equipment and media wear, etc.
Numerous other industrial bulk material processed experience similar problems in their size reduction requirements. This invention proposes to solve some of these problems with its extremely high speed, very low energy requirements per ton of feed, low wear on interior surface of the equipment, automatic internal air classification of the product, compact size of the equipment, ability to receive relatively large size feed while reducing to very fine size product, and easily performed maintenance when needed.